Assessing the frequency of deep lingual concavities in 826 posterior mandible sockets

PURPOSE: To evaluate the frequency of deep lingual concavities in the lower jaw, which can cause surgical complications while inserting dental implants. METHODS: Cross-sections of the mandible alveolar ridge at the edentulous sockets were obtained via cone-beam computed tomography. Measurements were carried out using the freeware 'IC Measure' and based on the basic definitions of a previous study. RESULTS: Most (767/826 = 93%) sockets had concavities of various degrees (30-90°), while 59 (7%) sockets had no concavity. However, the majority of the concavities (71%) were mild, with angles > 60°. The other 220 (26%) sockets had deeper concavities of <60°; among these, 12 (1%) had extremely deep concavities of <40°. CONCLUSIONS: Only a few cases have deep lingual concavities that pose a high risk for lingual plate perforation during dental implantation.